Process of improving the magnetic qualities of iron-silicon-manganese alloys.



UNITED sTArEs PATENT OFFICE.

ROBERT A. HADFIELD, OF SHEFFIELD, ENGLAND.

PROCESS OF IMPROVING THE MAGNETIC QUALITIES 0F IRON-SILICON-MANGANESE ALLOYS.

To all whom it may concern:

Be it known that I, ROBERT ABBOTT HAD- FIELD, a subject of the King of Great Britain, residing at Sheflield, England, have invented a certain new and useful Improvement in Processes for Improving the Magnetic Qualities of Iron- Silicon Manganese Alloys, of which the following is a specification,

In United States Letters Patent No. 745,829 granted to me December 1 1903, I

have described and claimed a process'ofprohigh permea bility and low hysteresis action which con-Y ducing a magnetic material 0 My present invention is a process of increasing the permeability and electric resistance and decreasing the hysteresls action of sald lron-sllicon-manganese alloy.

Specification of Letters Patent.

Application filed July 5, 1906. Serial No. 324,893.

Patented Nov. 27, 1906.

I carry my said process into efi'ect by melting together the ingredients in a suitable vessel, casting into ingots, rolling or working and treating the same by first heating the alloy to between about 900 and 1,100 centigrade, then allowing it to cool, then reheating to between 700 and 850 centigradethat is, to a temperature lower than the one at- I claim- The process of producing a magnetic alloy of high magnetic permeability and electric resistance and low hysteresis action, which consists in adding to an alloy of iron and s licon an admixture of manganese in proportion not suflicient to impair said magnetic qualities, then heating said iron-silicon-manganese, alloy to a relatively high temperature below its melting-point, allowing the alloy to cool, reheating it to a temperature below that first employed, and finally cooling.

In witness whereof I have signed my name hereto in the presence of two witnesses.

ROBERT A HADFIELD.

Witnesses:

'HENRY E. DIXON,

FRANK HUTsoN.

tained during the first heating. and thenfinally' 

